JP6425680B2 - Low temperature tank - Google Patents

Description

  According to the present invention, the shell wall forming the storage space inside is formed of at least two layers of heat insulating walls, and the heat insulating space between the heat insulating walls juxtaposed in the thickness direction is in a reduced pressure state excluding gas. The storage space relates to a low temperature tank capable of storing a low temperature medium.

  Conventionally, what is called a vacuum panel from which the gas in the internal space has been removed has been considered as the heat insulator (see, for example, Patent Document 1 and Patent Document 2 and Patent Document 3).

Unexamined-Japanese-Patent No. 11-159694 Japanese Patent Application Publication No. 2013-532807 Japanese Patent Publication No. 2009-509109

The conventional low-temperature tank described above can increase the heat insulation performance to the storage space by eliminating the gas and reducing the pressure to a vacuum or a vacuum close to the heat insulation space between the heat insulation walls juxtaposed in the thickness direction It is considered to be composed (Japan Mechanical Engineering Society, "heat transfer engineering materials", Maruzen Publishing Co., Ltd., March 11, 2013, P208-209), (edited by Tadanori Misawa, "Separate Chemical Industry 28- 10 New Supplemental Vacuum, issued by Chemical Industry Co., Ltd. June 10, 1985, pp. 166-175).
Therefore, the larger the storage space becomes, the larger the adiabatic space becomes, and in order to maintain the reduced pressure state of the adiabatic space of the low temperature tank high, it is necessary to periodically discharge the gas in the decompressed space.
However, when vacuum destruction of the adiabatic space occurs due to an accident such as an earthquake, for example, the adiabatic performance drops sharply and the stored matter in the storage space is kept in a cryogenic state such as liquid hydrogen. In the case of a low temperature medium which must be used, there is a risk of bumping.
Therefore, for example, in the heat insulating space, the heat insulating body whose internal space has been decompressed in advance is disposed so as to cover the surface of the heat insulating wall, and the air in the heat insulating space is exhausted. It is conceivable to be able to maintain the thermal insulation performance of the low temperature tank at least by the thermal insulation even if the adiabatic failure occurs.
However, if the degree of pressure reduction of the thermal insulation space of the low temperature tank is higher than the internal space of the thermal insulation, the residual gas inside the thermal insulation expands and the force is applied to the exterior material to cause deformation, possibly causing destruction. There was a danger.

  Therefore, an object of the present invention is to solve the above-mentioned problems and to maintain the low temperature insulation performance of the low temperature tank high.

  The first low temperature tank according to the present invention is characterized in that an outer shell wall for forming a storage space capable of storing a low temperature medium therein is formed of at least two layers of heat insulating wall and arranged in parallel in the thickness direction. Between the heat insulating walls, there is provided a heat insulating space in which the gas is removed and the pressure is reduced, and among the heat insulating walls, the relative position between the first heat insulating wall on the storage space side and the second heat insulating wall outside the tank. On each of the facing surfaces, a multilayer material in which aluminum foil and glass net are laminated is attached to the outer surface of the first heat insulating wall, and the inside can be formed as an airtight space on the inner surface of the second heat insulating wall. Form an airtight container with an external packaging material, and accommodate the spacer member for maintaining the internal space against the external pressure in the internal space of the airtight container, and communicate with the heat insulation space to form the internal It allows the discharge of gas from the inside of the space to the adiabatic space. A plurality of heat insulators provided in the airtight container with check valves for preventing gas from entering the inner space from the heat insulation space, side by side to cover the inner surface of the second heat insulation wall, in the heat insulation space; The multilayer material and the heat insulator are disposed at a distance from each other.

According to the first feature configuration of the present invention, since the heat insulating body installed in the heat insulating space is provided with the check valve in the airtight container, the inside of the heat insulating body when removing the gas from the heat insulating space The gas in the space is also drawn together, the pressure in the insulation tank of the low temperature tank and the internal space of the insulation become the same pressure, pressure does not act on the exterior material of the insulation, and its performance can be maintained over a long period.
Furthermore, even if the vacuum insulation of the adiabatic space occurs unexpectedly and the degree of reduced pressure decreases and the cold storage performance is reduced, the internal space of the thermal insulator is prevented from invading gas from the outside by the check valve. Is maintained at a low pressure.
Therefore, the low temperature tank can suppress the fall of the cold storage performance with respect to the storage space of a low temperature medium by the heat insulator which covers the inner surface of a heat insulation wall.

  According to a second feature of the present invention, the heat insulating wall is formed by forming an outer shell wall forming a storage space capable of storing a low temperature medium therein from at least two layers of heat insulating walls and juxtaposed in the thickness direction There is provided an insulation space between which a gas is removed to be in a reduced pressure state, and among the insulation walls, the opposing surfaces of the first insulation wall on the storage space side and the second insulation wall on the outside of the tank are provided. In each case, a multi-layer material in which aluminum foil and glass net are laminated is attached to the outer surface of the first heat insulating wall, and an outer covering material capable of forming the inside into an airtight space on the inner surface of the second heat insulating wall. Forming an airtight container, and accommodating a spacer member for maintaining the internal space against the external pressure in the internal space of the airtight container, and enabling the internal space and the heat insulation space to be communicated with each other. The airtight container is provided with an on-off valve composed of an electromagnetic on-off valve. A large number of heat bodies are lined up to cover the inner surface of the second heat insulating wall, and in the heat insulating space, the multilayer material and the heat insulating body are spaced apart to make the heat insulating space airtight. The open / close valves can be opened and closed from the outside of the outer shell wall.

According to the second characteristic configuration of the present invention, the heat insulating body provided in a large number in the heat insulating space is provided with an on-off valve consisting of an electromagnetic on-off valve, and from the outside of the shell wall in a state where the heat insulating space is airtight. In order to enable the opening and closing operation, when the gas is removed from the adiabatic space, by opening the on-off valve, the gas in the inner space of the adiabatic body is also sucked, and the adiabatic space of the low temperature tank and the adiabatic body The pressure in the interior space is the same, pressure does not act on the insulation of the insulation, and its performance can be maintained for a long time.
In addition, if the on-off valve is closed after depressurizing the inside of the adiabatic space, even if the vacuum insulation of the adiabatic space unexpectedly occurs and the degree of depressurization decreases and the cold storage performance declines, The internal space of the heat insulator is maintained at a low pressure by preventing the gas from invading from the outside by a closed valve, and the low temperature tank cools the storage space of the low temperature medium by the heat insulator covering the inner surface of the heat insulation wall. Performance degradation can be suppressed.

  According to a third aspect of the present invention, the heat insulating wall is formed by forming an outer shell wall forming a storage space capable of storing a low temperature medium therein from at least two layers of heat insulating walls and juxtaposed in the thickness direction There is provided an insulation space between which a gas is removed to be in a reduced pressure state, and among the insulation walls, the opposing surfaces of the first insulation wall on the storage space side and the second insulation wall on the outside of the tank are provided. In each case, a multi-layer material in which aluminum foil and glass net are laminated is attached to the outer surface of the first heat insulating wall, and an outer covering material capable of forming the inside into an airtight space on the inner surface of the second heat insulating wall. Forming an airtight container, and accommodating a spacer member for maintaining the internal space against the external pressure in the internal space of the airtight container, and enabling the internal space and the heat insulation space to be communicated with each other. A large number of heat insulators provided in the airtight container with a plurality of on-off valves. 2) Cover the inner surface of the heat insulation wall, arrange the space between the multi-layer material and the heat insulation in the heat insulation space, configure the on-off valve from a normally open on-off valve, and A first detector is provided for detecting that the degree of pressure reduction has decreased by a set value or more, and an automatic valve closing device for closing the on-off valve based on the detection by the first detector is provided.

According to the third feature configuration of the present invention, when the gas is removed from the heat insulation space, the on / off valve is always in the open state, so the gas in the internal space of the heat insulation is sucked together, The pressure is not the same as the internal space of the heat insulator, and pressure does not act on the exterior material of the heat insulator. Therefore, no external force is applied to the spacer, and the performance can be maintained for a long time.
Furthermore, even if the vacuum insulation of the adiabatic space occurs unexpectedly and the degree of pressure reduction decreases and the cold storage performance is lowered, the internal space of the thermal insulator is operated in the state where the on-off valve is closed by the automatic valve closing device. As a result, the low temperature tank is maintained at a low pressure by preventing the entry of gas from the outside, and the low temperature tank can maintain the cold storage performance to the storage space of the low temperature medium by the heat insulator covering the inner surface of the heat insulation wall.

  According to a fourth characterizing feature of the present invention, the low temperature medium is liquid hydrogen.

  According to the fourth aspect of the present invention, safe storage of liquid hydrogen, which requires particularly high cooling performance, can be improved.

It is a whole longitudinal cross-sectional view of a low temperature tank. It is a principal part longitudinal cross-sectional view of a low temperature tank. It is a principal part longitudinal cross-sectional view of the low temperature tank of another embodiment.

Embodiments of the present invention will be described below based on the drawings.
In recent years, general use of liquid hydrogen tends to be promoted from the viewpoint of reduction of greenhouse gases and energy security, as shown in Fig. 1 for thermal power generation using hydrogen / fuel cells and liquid hydrogen. A thermal insulation wall comprising an outer shell wall forming a storage space S capable of storing liquid hydrogen 1 as a low-temperature medium inside, at least two layers of a first thermal insulation wall 2A and a second thermal insulation wall 2B 2 and the heat insulation space V between the first heat insulation wall 2A and the second heat insulation wall 2B arranged in parallel in the thickness direction constitutes a low temperature tank 3 in a reduced pressure state in which gas is removed.

In general, liquid hydrogen 1 is very easy to evaporate as compared to LNG, and for its storage, it must be stored at or below 253 ° C. (boiling point), so the adiabatic space V is highly adiabatic. -It is formed by the outer shell wall structure which maintains high strength, and the pressure reduction state is made into the vacuum state of 10 ^-2 Pa-10 ^-3 Pa, for example with a vacuum pump etc.

  Among the plurality of thermal insulation wall bodies 2 forming the thermal insulation space V, the first thermal insulation wall body 2A on the storage space S side is a multilayer material 4 in which aluminum foil and glass net are laminated on the outer surface on the thermal insulation space V side. In addition, the heat insulator 5 is installed on the inner surface facing the heat insulation space V on the second heat insulation wall 2B outside the tank to cover the inner surface of the second heat insulation wall 2B.

First Embodiment
The heat insulator 5 of the first embodiment is, as shown in FIG. 2, an airtight container 6 formed of an exterior material in which a metal foil such as aluminum foil and a resin sheet capable of forming the inside into an airtight space are laminated. Spacer member 7 for maintaining the internal space against the external pressure made of glass fiber material, pearlite, silica powder, hard urethane foam, airgel, etc. is housed in the internal space of airtight container 6, and from the inside of the internal space to the outside The airtight container 6 is provided with a non-return valve 8 which allows the gas to be discharged to the inside and prevents the gas from entering from the outside to the inside.

  In the low temperature tank 3 for liquid hydrogen storage, a device for controlling the degree of vacuum of the adiabatic space V at a constant level and adjusting and maintaining the degree of vacuum periodically is provided (not shown).

Second Embodiment
As the heat insulator in the second embodiment, an airtight container is formed of an outer covering material capable of forming an inner space in an airtight space, and a spacer member for maintaining the inner space against the external pressure in the inner space of the airtight container. The airtight container is provided with an open / close valve which can be switched and operated between an open state in which the internal space communicates with the outside and a closed state in which the internal space is airtight.
Then, many heat insulators are installed in the heat insulation space on the outer heat insulation wall side to cover the inner surface of the heat insulation wall, and the on / off valves are constituted by electromagnetic on / off valves to make the heat insulation space airtight. A low temperature tank is constructed in which the on-off valves can be opened and closed from the outside of the shell wall.
Therefore, in this case, by opening the on-off valve when removing the gas from the adiabatic space, the gas in the internal space of the adiabatic body is also drawn together, and the adiabatic space of the low temperature tank and the internal space of the adiabatic body The same pressure is applied, and no pressure is applied to the outer covering of the heat insulator, so that no external force is applied to the spacer, and its performance can be maintained over a long period of time.
In addition, if the on-off valve is closed after depressurizing the inside of the adiabatic space, even if the vacuum insulation of the adiabatic space unexpectedly occurs and the degree of depressurization decreases and the cold storage performance declines, The internal space of the heat insulator is maintained at a low pressure by preventing the gas from invading from the outside by a closed valve, and the low temperature tank cools the storage space of the low temperature medium by the heat insulator covering the inner surface of the heat insulation wall. Performance can be maintained.

Third Embodiment
An outer shell wall forming a storage space capable of storing a low-temperature medium inside is formed of at least two layers of thermal insulation walls, and the thermal insulation space between the thermal insulation walls juxtaposed in the thickness direction is a reduced pressure state excluding gas. As a third embodiment of the present invention, a spacer for forming an airtight container with an exterior material capable of forming the inside as an airtight space, and maintaining the internal space against the external pressure in the internal space of the airtight container. An airtight container is provided with a normally open on-off valve which can be switched between an open state in which the internal space and the outside are communicated and a closed state in which the internal space is kept airtight. A large number of heat insulators are installed in the heat insulation space on the outer heat insulation wall side to cover the inner surface of the heat insulation wall, and it is detected that the degree of pressure reduction in the heat insulation space is reduced by a set value or more Providing a detector, based on the detection by the first detector Have configured cold tank is provided an automatic closing device for closing operations closing.
Therefore, when removing the gas from the adiabatic space, the on-off valve is normally open, so the gas in the internal space of the thermal insulator is also sucked, and the thermal insulation space of the low temperature tank and the internal space of the thermal insulator have the same pressure. As a result, pressure does not act on the sheathing of the heat insulator, so that no external force is applied to the spacer, and its performance can be maintained over a long period of time.
Furthermore, even if the vacuum insulation of the adiabatic space occurs unexpectedly and the degree of pressure reduction decreases and the cold storage performance is lowered, the internal space of the thermal insulator is operated in the state where the on-off valve is closed by the automatic valve closing device. As a result, the low temperature tank is maintained at a low pressure by preventing the entry of gas from the outside, and the low temperature tank can maintain the cold storage performance to the storage space of the low temperature medium by the heat insulator covering the inner surface of the heat insulation wall.

[Another embodiment]
Other embodiments will be described below.
<1> The airtight container 6 of the said heat insulator 5 may form the airtight container 6 from metal plates, such as a stainless plate, for example other than what laminated | stacked metal foil and the resin sheet. And the shape may be block shape other than panel shape.
<2> The spacer member 7 may be a material or a structural member having low thermal conductivity and good air permeability other than glass fiber material, pearlite, silica powder, hard urethane foam, airgel, etc. For example, it may be one molded from a porous ceramic material.
<3> The low temperature tank 3 may be capable of storing liquid nitrogen, liquid oxygen, liquid helium or the like in the storage space S in addition to the liquid hydrogen 1.
<4> The check valve 8 is, as shown in FIG. 2, in addition to the one provided at one end of the airtight container 6, the center of the surface of the airtight container 6 facing the heat insulation space V as shown in FIG. It may be provided in a part. In any case, it is sufficient if the airtight container 6 is provided with a check valve 8 which allows the gas to be discharged from the inside to the outside of the inner space of the airtight container 6 and prevents the inflow of the gas from the outside to the inside. .

  As mentioned above, although the reference numerals are given to make the contrast with the drawings more convenient, the present invention is not limited to the configuration of the attached drawings by the description. Moreover, of course in the range which does not deviate from the summary of this invention, it can implement in a various aspect.

2 Thermal insulation wall 5 Thermal insulation 6 Airtight container 7 Spacer member 8 Check valve S Storage space V Thermal insulation space

Claims (4)

An outer shell wall forming a storage space capable of storing a low-temperature medium inside is formed of at least two layers of thermal insulation walls, and gas is eliminated between the thermal insulation walls juxtaposed in the thickness direction to reduce pressure. Provide an adiabatic space that has been
Among the heat insulation walls, aluminum foil and glass are formed on the outer surface of the first heat insulation wall on the opposing surfaces of the first heat insulation wall on the storage space side and the second heat insulation wall on the outer side of the tank. Attach a multi-layered material in which nets are stacked,
An airtight container is formed on the inner surface of the second heat insulating wall with an outer covering material capable of forming an internal airtight space, and the internal space of the internal airtight container is maintained against the external pressure to maintain the internal space. And allowing the gas to be discharged from the inside of the internal space to the adiabatic space and preventing the gas from entering the internal space from the adiabatic space. A large number of heat insulators in which the check valve is provided in the airtight container are arranged to cover the inner surface of the second heat insulation wall, and in the heat insulation space, the multilayer material and the heat insulator are spaced apart. Low temperature tank. An outer shell wall forming a storage space capable of storing a low-temperature medium inside is formed of at least two layers of thermal insulation walls, and gas is eliminated between the thermal insulation walls juxtaposed in the thickness direction to reduce pressure. Provide an adiabatic space that has been
Among the heat insulation walls, aluminum foil and glass are formed on the outer surface of the first heat insulation wall on the opposing surfaces of the first heat insulation wall on the storage space side and the second heat insulation wall on the outer side of the tank. Attach a multi-layered material in which nets are stacked,
An airtight container is formed on the inner surface of the second heat insulating wall with an outer covering material capable of forming an internal airtight space, and the internal space of the internal airtight container is maintained against the external pressure to maintain the internal space. Of the heat insulating body in which the heat insulating container is provided with a plurality of open / close valves, each of which is provided with an open / close valve that accommodates the spacer member and allows the internal space and the heat insulation space to communicate with each other. Covering the inner surface of the heat insulating space, the multi-layer material and the heat insulating body are spaced apart from each other, and the on-off valves are opened and closed from the outside of the outer shell wall with the heat insulating space sealed. Low temperature tank that has been operated. An outer shell wall forming a storage space capable of storing a low-temperature medium inside is formed of at least two layers of thermal insulation walls, and gas is eliminated between the thermal insulation walls juxtaposed in the thickness direction to reduce pressure. Provide an adiabatic space that has been
Among the heat insulation walls, aluminum foil and glass are formed on the outer surface of the first heat insulation wall on the opposing surfaces of the first heat insulation wall on the storage space side and the second heat insulation wall on the outer side of the tank. Attach a multi-layered material in which nets are stacked,
An airtight container is formed on the inner surface of the second heat insulating wall with an outer covering material capable of forming an internal airtight space, and the internal space of the internal airtight container is maintained against the external pressure to maintain the internal space. A plurality of heat insulators in which the air tight container is provided with an open / close valve that accommodates the spacer member and allows the internal space and the heat insulation space to communicate with each other, and covers the inner surface of the second heat insulation wall; In the space, the multi-layered material and the heat insulator are spaced apart,
The on-off valve is composed of a normally open on-off valve, and
A first detector is provided to detect that the degree of pressure reduction in the adiabatic space has decreased by a set value or more.
A low temperature tank provided with an automatic valve closing device for closing the on-off valve based on detection by the first detector.   The low temperature tank according to any one of claims 1 to 3, wherein the low temperature medium is liquid hydrogen.

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